// This file is part of Eigen, a lightweight C++ template library // for linear algebra. Eigen itself is part of the KDE project. // // Copyright (C) 2006-2008 Benoit Jacob // // Eigen is free software; you can redistribute it and/or // modify it under the terms of the GNU Lesser General Public // License as published by the Free Software Foundation; either // version 3 of the License, or (at your option) any later version. // // Alternatively, you can redistribute it and/or // modify it under the terms of the GNU General Public License as // published by the Free Software Foundation; either version 2 of // the License, or (at your option) any later version. // // Eigen is distributed in the hope that it will be useful, but WITHOUT ANY // WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS // FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the // GNU General Public License for more details. // // You should have received a copy of the GNU Lesser General Public // License and a copy of the GNU General Public License along with // Eigen. If not, see . #ifndef EIGEN_DIAGONALCOEFFS_H #define EIGEN_DIAGONALCOEFFS_H /** \class DiagonalCoeffs * * \brief Expression of a sub/main/super diagonal of a matrix * * \param MatrixType the type of the object in which we are taking s sub/main/super diagonal * \param DiagId the index of the sub/super diagonal. The default is 0 and it means the main diagonal. * * The matrix is not required to be square. * * This class represents an expression of the main diagonal, or any sub/super diagonal * of a square matrix. It is the return type of MatrixBase::diagonal() and most of the * time this is the only way it is used. * * \sa MatrixBase::diagonal() */ template struct ei_traits > { typedef typename MatrixType::Scalar Scalar; typedef typename ei_nested::type MatrixTypeNested; typedef typename ei_unref::type _MatrixTypeNested; enum { AbsDiagId = DiagId<0 ? -DiagId : DiagId, RowsAtCompileTime = int(MatrixType::SizeAtCompileTime) == Dynamic ? Dynamic : (EIGEN_ENUM_MIN(MatrixType::RowsAtCompileTime, MatrixType::ColsAtCompileTime) - AbsDiagId), ColsAtCompileTime = 1, MaxRowsAtCompileTime = int(MatrixType::MaxSizeAtCompileTime) == Dynamic ? Dynamic : (EIGEN_ENUM_MIN(MatrixType::MaxRowsAtCompileTime, MatrixType::MaxColsAtCompileTime) - AbsDiagId), MaxColsAtCompileTime = 1, Flags = (unsigned int)_MatrixTypeNested::Flags & (HereditaryBits | LinearAccessBit), CoeffReadCost = _MatrixTypeNested::CoeffReadCost }; }; template class DiagonalCoeffs : public MatrixBase > { enum { AbsDiagId = DiagId<0 ? -DiagId : DiagId, OffsetRow = DiagId<0 ? -DiagId : 0, OffsetCol = DiagId<0 ? 0 : DiagId }; public: EIGEN_GENERIC_PUBLIC_INTERFACE(DiagonalCoeffs) inline DiagonalCoeffs(const MatrixType& matrix) : m_matrix(matrix) {} EIGEN_INHERIT_ASSIGNMENT_OPERATORS(DiagonalCoeffs) inline int rows() const { return std::min(m_matrix.rows(), m_matrix.cols()) - AbsDiagId; } inline int cols() const { return 1; } inline Scalar& coeffRef(int row, int) { return m_matrix.const_cast_derived().coeffRef(row+OffsetRow, row+OffsetCol); } inline const Scalar coeff(int row, int) const { return m_matrix.coeff(row+OffsetRow, row+OffsetCol); } inline Scalar& coeffRef(int index) { return m_matrix.const_cast_derived().coeffRef(index+OffsetRow, index+OffsetCol); } inline const Scalar coeff(int index) const { return m_matrix.coeff(index+OffsetRow, index+OffsetCol); } protected: const typename MatrixType::Nested m_matrix; }; /** \returns an expression of the main diagonal of the matrix \c *this * * \c *this is not required to be square. * * Example: \include MatrixBase_diagonal.cpp * Output: \verbinclude MatrixBase_diagonal.out * * \sa class DiagonalCoeffs */ template inline DiagonalCoeffs MatrixBase::diagonal() { return DiagonalCoeffs(derived()); } /** This is the const version of diagonal(). */ template inline const DiagonalCoeffs MatrixBase::diagonal() const { return DiagonalCoeffs(derived()); } /** \returns an expression of the \a Id-th sub or super diagonal of the matrix \c *this * * \c *this is not required to be square. * * The template parameter \a Id represent a super diagonal if \a Id > 0 * and a sub diagonal otherwise. \a Id == 0 is equivalent to the main diagonal. * * Example: \include MatrixBase_diagonal_int.cpp * Output: \verbinclude MatrixBase_diagonal_int.out * * \sa MatrixBase::diagonal(), class DiagonalCoeffs */ template template inline DiagonalCoeffs MatrixBase::diagonal() { return DiagonalCoeffs(derived()); } /** This is the const version of diagonal(). */ template template inline const DiagonalCoeffs MatrixBase::diagonal() const { return DiagonalCoeffs(derived()); } #endif // EIGEN_DIAGONALCOEFFS_H